Windshield wiper motor



y 1, 1954 F. SPRAGUE ET AL 2,678,029

WINDSHIELD WIPER MOTOR Filed 001;. 23, 1948 3 Sheets-Sheet 1 22 a? 56 ffINVENTORS Fen/xix \SPEAGUE M, 5.4 ro/v f: NICHOL 5.

5) W54 YW.

ATTOIYIVEYS F. SPRAGUE ET AL May 11, 1954 WINDSHIELD WIPER MOTOR 3Sheets-Sheet 2 Filed Oct. 23, 1948 FzAA K SPEAGUE AND INVENTOR.

E1. raw /V/6/1'0Z s.

arm W,

ATTORNEYJ Patented May 11, 1954 UNITED STATES TENT OFFlCE WINDSHIELDWIPER MOTOR Application October 23, 1948, Serial No. 56,066

10 Claims.

at i

This invention relates to improvements in windshield wiper motors, andparticularly to a motor actuated by fluid under pressure, such as bycompressed air.

The objects of this invention are to provide a motor of this type whichis of simple, sturdy and inexpensive construction, which is easy toassemble and disassemble, which is provided a novel and simple valvemeans for controlling the flow of fluid therein, which utilizes acombination and arrangement of parts which will insure trouble-freeoperation of the motor, which includes means for quickly and easilyvarying the stroke of the motor, and which includes novel quick-throwmeans for reversing the direction of operation or" the motor as itreaches the opposite ends of its stroke.

Other objects will be apparent from the following specification.

In the drawings:

1 is a view of the motor in elevation mounting a windshield wiper blade.

Fig. 2 a longitudinal sectional view of the motor taken on line 2-2 ofFig. 3.

Fig. 3 is a longitudinal sectional View of the motor taken on line t-3of Fig. 2.

Fig. 4 is a transverse sectional view of the motor taken on line l-t ofFig. 2.

5 is an enlarged. longitudinal sectional view of the valve element ofthe motor taken on line 5'5 of Fig. 4 and illustrating the valve in oneoperative position.

Fig. 6 is a longitudinal sectional view of the valve similar to Fig. .5out illustrating the same in a second operative position.

Fig. '1 is a view of the motor with the parts shown in section andillustrating the relation of the valve to the motor.

8 is fragmentary transverse sectional view taken on line 88 of Fig. 5.

Referring to the drawings which illustrate the preferred embodiment ofthe invention, the numeral it designates a motor housing which ispreferably formed of two similar substantially cup-shaped partsassembled in axial alignment to define a unit having an elongated boreclosed at its ends. Each of the housing parts comprises a cylindricalportion H, a closed end wall it, and an enlarged portion is at the openend portion thereof. The cup shaped housing parts are preferably cast ormolded and may comprise die castings or other metal castings or may beformed of molded plastic material. The bore of the cylindrical portion 9l of each part is preferably circular in cross-section and of uniformdimension and is enlarged at the mouth portion !3 of each part,providing a circumferential shoulder i l in the interior of each partbetween the cylindrical and enlarged portions of the bore. As bestillustrated in Fig. 'l, the cylindrical bore portion of each part isinterrupted by a longitudinal groove it; which extends from its innerend to a point adjacent to but spaced from the shoulder it, and theinner end of this groove communicates with a notch is formed in acircumferential shoulder l'l formed in the casting. lhe opposite end ofthe groove :5 communicates with a transverse outwardly extendingaperture :3 which is open at the outer surface of the casting. Apre-formed metal sleeve or tube it has a snug fit within the cylindricalbore of each housing part, the same preferably being a press or drivefit, and the inner end of each sleeve bears against the circumferentialshoulder ll of the casting. The opposite end of each sleeve is flaredoutwardly at 20 to bear against the shoulder i l of the casting. Anysuitable means (not shown) may be provided for securing the mouthportions of the two cup-shaped housing members in registeringsubstantially sealed engagement.

A power take-off shaft 21 adapted to mount a windshield wiper arm andblade 22 is mounted within a sleeve 23, extending transversely of thehousing at the longitudinal center thereof and preferably offsetlaterally relative to the longitudinal axis of the housing, as bestshown in Fig. 2. The axes of the shaft 2! and the sleeve 23 preferablylie in the parting plane of the two parts of the housing ill. Thehousing is provided at one end with an aperture of larger diameter thanthe sleeve 23 and receives a bearing it encircling said sleeve, asillustrated in Fig. 3, and a flanged sleeve 25 against which the outerend of the bearing 2% engages. A split ring 28 encircles the sleeve '23and preferably seats in a circumferential groove therein to bear againstthe inner end of the bearing 2i. It will be understood that the flangeii of the sleeve 25 is accommodated and positioned within a receivinggroove in the housing by pro-assembling the shaft 2|, sleeve 23, bearing26, sleeve 25 and ring 26 and positioning this assembly between theparts of the housing incident to the assembly of the housing parts. Thispreassembly is accommodated by the provision of the end of the shaft 2!,shown at the bottom in Fig. 3, with an axial screw-threaded bore toreceive a screwthreaded bolt 28 whose head serves to clamp a disk 29against the ends of said shaft and sleeve, said housing parts at theirmouths being provided with complementary notches which receive the head38 of the bolt 23 freely therein.

The sleeve 23 fixedly mounts a pinion 3| thereon intermediate its ends.A spacer or collar 32 encircles the sleeve 23 and bears thereagainst atone edge. A quick-throw plate 33 has an opening therein intermediate itsends having a free fit upon the sleeve 23 to accommodate relativerotation of said sleeve and said quick-throw plate. A cylindrical spacer34 bears against the quickthrow plate at one end thereof and fits withina socket formed in the interior of the housing it at its opposite end.The quick-throw plate 33 has a transversely elongated arcuate opening 35formed in one end thereof, illustrated in Fig. 2 as the lower end, forpurposes to be described hereinafter. The opposite end of the plate 33is provided with a pair of converging angularly disposed surfaces 35which define a pointed end portion of said plate. The confronting mouthsof the two housing portions are provided with semicircular notches at apoint aligned with the plate and cup-shaped member 3? is received in thebore defined by said registering notches. The cup 3? will preferablyhave an adjustable screw-threaded connection with the housing, and theouter or closed end 38 of the cup 3? is positioned outermost. A coilspring 39 is received within the cup member 31, and a ball 40 isslidable in said cup-shaped member, being normally inwardly urged by thespring The operative relation of the quick-throw parts is bestillustrated in Fig. 2, wherein it will be seen that the spring serves topress the ball 45 into engagement with one or the other of the faces 36of the quick-throw plate 33 and to hold said plate in one of twooppositely tilted positions with respect to the transverse parting planebetween the two parts of the housing.

A piston unit is received within and shiftable within the housing Ill.This piston unit includes a longitudinal bar 45 located eccentrically inthe bore of said housing and mounting at its opposite ends rigidtransverse end plates 46 substantially concentric with the bore of thehousing. The elongated bar 45 includes a toothed rack portion 3: whoseteeth mesh with the teeth of the pinion 31. The central portion 43 of acup-shaped sealing member bears against the outer surface of eachtransverse plate portion 46 and is of a size and shape such that itscylindrical marginal portion 49 has a snug fit within one of the sleeves19. A spacer disk 50 bears against the outer surface of the centralportion Q8 of each cup-shaped seal, and a positioning disk bears againstthe outer surface of the spacer 59 and has a curled marginal flange 52engaging the inner surface of the cylindrical portion 453 of the seal tohold the same in continuous circumferential engagement with the sleeveIt. A clamp plate 53 bears against the outer surface of the member 5!. Ascrew or other securing member 54 extends axially through the pistonassembly constituting the parts 46-53 and is anchored in the transverseplate t6, whereby the component parts of each piston are securely heldin assembled relation. An elongated screw-threaded rod 55 is carried byand extends between the piston plate portions 46 in offset relation tothe bar 45 and parallel to the axis of the housing iii. If desired, thisunit may comprise two threaded studs each carried by one of said plates46 and connected by 4 an internally screw-threaded sleeve 56. Thethreaded rod '55 is preferably located to pass below the spacer sleeve32 clear of the quick-throw plate 33 and has mounted thereon a pair ofnuts 5'! and 58 for adjustment longitudinally of said shaft andsubstantially equally spaced from and adjacent to the transverse pistonplate portions 46. These nuts 51 and 58 may be of any suitableconstruction and are located on opposite sides of the quick-throw member33 in all operative positions of the device and are engageable with saidquick-throw member in their movement with the piston unit from one toanother operative position of said piston unit. The confronting faces ofthe two housing parts are cut away at a point diametrically opposite thesleeve 31 to define a notch 59 which receives a roller 60 havingprojecting axial studs 6i which are journaled in the housing. Thisroller bears against the longitudinal bar 45 at its lower surface at apoint opposite the point of engagement with the pinion 3! with the rack41. In the preferred form of the device, as best illustrated in Fig. 4,the roller 60 is of stepped construction, having a portion 62 of onediameter and a portion 63 of a slightly smaller diameter. The bottomsurface of the bar 45 is likewise stepped, as best seen in Fig. 4, sothat it engages both of the roller portions 62 and 63 and any tendencyof the bar 45 to twist is resisted.

The housing ID has a longitudinal inset portion or notch in its outersurface defined by the surfaces 65 and 66, as best seen in Fig. 4. Theface 66 at the longitudinal center of the casing is interrupted by alongitudinally elongated slot 61 with which a portion of the elongatedaperture 35 of the quick-throw plate 33 registers at all times. Apre-formed valve unit having a housing 88 with surfaces adapted to fitin face engagement with the surfaces 65 and 66 of the inset of the motorhousing is seated in said inset or notch and is fixedly secured theretoin any suitable manner.

The construction of the re-formed valve contained within the housing 68is best illustrated in Figs. 5 and 6. The housing 68 has an elongatedbore 69 formed therein and open at 10 at one end of said housing. Theopposite end of said bore is closed by the housing end wall H. The valvehousing 68 may comprise a metal casting, a die casting or a moldedplastic part. The bore 69 is interrupted by a longitudinal groove F2extending for the major portion of the length thereof but terminatingspaced from its opposite ends. The housing 68 also includes alongitudinal offset portion 13, and at this offset portion 13 the bore69 is interrupted by a second longitudinal groove 14. An intake passage15, which is preferably screw-threaded, is formed in the projection i3and communicates .with the groove 14 preferably at its center.

A pre-formed metal sleeve 16 of a length shorter than the groove 12 fitssnugly within the bore 559 and is preferably located intermediate thelength of said groove 12 whereby the opposite ends of said groove 12 arepermitted to communicate with the bore 69. The sleeve 16 is providedwith a pair of longitudinally spaced apertures T! and 73 whichcommunicate with the groove 14 adjacent the opposite ends of saidgroove. In longitudinally spaced relation to these apertures H and 18,the sleeve 76 is provided with apertures 19 and 80 preferably projectingradially substantially degrees displaced from the radius along which theapertures IT and 13 extend. The apertures 19 and 8|] register andcommunicate with lateral bores 8| formed in the valve housing 68, andsaid valve housing has neck portions 82 projecting therefrom in axialalignment with said bores 8!, as best seen in Fig. 8. These necksproject into sockets 83 formed in the motor casing ill open at the face65 thereof. Annular seals 84 iit in said sockets 83 and encircle thenecks 82 to provide a seal preventing leakage between the motor housingin and the valve housing 68 at the outlets of said bores ill. The bores81 communicate with the passages [8.

An elongated rigid member 85 of a cross-sectional size slightly smallerthan the inner diameter of the valve sleeve "N5 fits within said sleeve,and a stud 8'5 is mounted thereon and projects radially therefromthrough a longitudinal slot 8? formed in the sleeve and registering witha slot 88 formed in the valve body and aligned with the slot 6?. Saidstud 86 projects through said slots 8?, 3 and 6'! and into thetransversely elongated opening 35 in the quick-throw plate 33.

A stud S29 is mounted upon each end of the member 85 preferably by meansof a reduced diameter screw-threaded portion 9| which fits within anaxial screw-threaded bore of the member 85. Each stud is provided with ashoulder 92 which engages in a socket of a cupshaped rigid member 93whose outer diameter is preferably slightly less than the inner diameterof the sleeve '55 to have a snug or free sliding fit therein. Acup-shaped flexible seal 94 has its central portion clamped between theconfronting ends of the members 85 and 93 and has a marginal portion 95extending toward or in the direction of the member 93 and preferablyencircling a portion thereof, said seal portion 95 fitting snugly withinand having a continuous circumferential sealed engagement with the innersurface of the sleeve 16. Each stud 98 has an axial screw-threaded borein its outer end receiving a screw-threaded bolt 96 having an enlargedhead 91. An annular member 98 of a diameter having a snug but freelysliding fit within the bore of the sleeve 16 is clamped between theouter end of each stud 90 and the head 91 of the bolt 96 threaded insaid stud. Each of the members 98 has a circumferential groove thereinwhich receives an annular resilient sealing member 99, such as an O-ringhaving a continuous circumferential sealed engagement with the innersurface of the sleeve 15.

In the operation of the device, assuming that the parts of the motor arepositioned as illustrated in Fig. 2, the parts of the valve will bepositioned as illustrated in Fig. 6. Fluid under pressure, such ascompressed air, will be supplied through the valve inlet port bysuitable conduit means (not shown) and will pass therefrom into thelongitudinal intake passage l4 and through the passages '31 and 18. Thesealing member as is positioned between the ports 11 and "it and,consequently, any fluid under pressure entering the sleeve is throughthe port l1 will be confined within the portion of said sleeve betweenthe seals 99 and 95. Fluid which enters the sleeve through the port '18will pass through said sleeve to the port 80 and thence through thecommunicating ports 8| and I8 into the longitudinal passage [5 at theright-hand end of the motor. Consequently the fluid under pressure whichdischarges from the passage l5 through the notch 68 at the outer endthereof into the bore of the motor acts upon the .outer surface of theright-hand piston unit shown in Fig. 2. This serves to shift the entirepiston unit to the left, as viewed in Fig. 1, and the meshing engagementof the rack 41 with the pinion 33 serves to rotate or oscillate thesleeve 23 and the shaft 2| for the purpose of moving the wiper blade 22.lhe fluid under pressure which remains within the outer left-hand end ofthe bore of the motor housing is discharged therefrom through the notchIS, the longitudinal passage 15, to the registering apertures 18 and 81for discharge through the port 19 of the valve. Fluid so discharged intothe sleeve TE from the port 19 flows longitudinally to the left in Fig.6 into the bore 69 and the left-hand end of the discharge passage 72 forexhaust through the outlet 10. This setting of the valve and how offluid under pressure continues until the right-hand nut 58 upon the rod55 engages the quick-throw member 33 and shifts the same to a positionover center. As soon as the point of quick-throw member 33 passes deadcenter, the ball 38 pressed by the spring 39 will bear against thesurface 36 opposite that which it engages in the Fig. 2 position of saidquick-throw member. The spring-pressed ball thus serves quickly to throwthe member 33 to a tilted position opposite that shown in Fig. 2. Asthis quick-throw action occurs the right-hand end of the slot 35 of themember 33 will engage the stud 8t and shift the same in the slots 61, 81and 38 of the motor housing and the valve housing, thereby shifting themember 85 and the associated shiftable parts of the valve to theposition illustrated in Fig. 5. In this position of the valve, theconnections of the fluid system are reversed so that delivery of fluidunder pressure for motor actuating purposes occurs at the left-hand endof the motor housing, as viewed in Fig. 2, and the right-hand end ofsaid motor housing is connected for the discharge or exhaust of fluidpressure.

The device possesses a number of outstanding advantages. Included amongthese advantages are the support for the longitudinal connector 45 ofthe piston unit which is afforded by the roller 59. This insures againstany possibility that the teeth of th pinion 4'! will slip any of theteeth of the pinion 3| and thereby assures a full stroke of the motor ineach direction. Another advantage is that the length of the stroke canbe varied at will by a very simple manipulation, namely, a change in theadjustment of the position of each of the nuts 51 and 58 upon thethreaded rod 55. Thus Where it is required by the physicalcharacteristics of the windshield and the mounting of the windshieldwiper motor thereon to have a throw of the wiper blade through apredetermined are of greater or lesser angular extent than i required bythe shape or other characteristic of a different windshield, thatdifference can be accommodated quickly without requiring any specialparts cr without requiring a construction specially designed to providethe desired throw. Thus by increasing the spacing of the parts 5'. and58, the angular displacement of the terminal positions of the wiperblade can be increased, and by decreasing the spacing of said nuts 5!and 58 the angular displacement of the terminal positions of the wiperblade can be decreased. Also, it is possible to change the terminalpositions of the wiper blade. This can be accomplished by positioningthe nuts 5'5 and 58 at different distances from the piston unitsadjacent thereto. This adiustability adapts this windshield wiperconstruction for universal ap- 7 plication and makes it possible to meetany mounting problem without any structural change of the device andmerely by a simple adjustment thereof.

Another advantage of the device is the construction of the valve withits four seals 95 and 99 which insure against the occurrence of anyleakage. Note in this connection that no leakage can occur betweeneither of the ports 11 and T8 and the openings 81, 88 and 81 in whichthe stud 8B shifts. Therefore no problem of the creation of pressurebetween the two pistons of the motor can occur, and no problem ofleakage of fluid under pressure from the valve can occur.

Other advantages pertaining to the construction of both the valve andthe motor housing resid in the cast formation of the housing and theinsertion therein of preformed sleeves. This avoids the necessity ofdifficult and time-consuming honing or finishing operations upon theunit and also simplifies the formation of the various passages extendinglengthwise of said unit, such as the passages of the motor housin unit12 and M of the valve unit.

Another feature of considerable advantag and importance in the device isthe ability to remove the shaft 2! without completely disassembling thedevice. Observe in this connection that all that is required to removesaid shaft 2| is the release of the bolt 28. Upon the removal of saidbolt the shaft 2! can he slid freely from the sleeve. Observe also thatthere is no danger of a freezing of the shaft within the sleeve and thatthe simple operation and manipulation of the bolt 28 to back the sameout of th receiving bore within the shaft 2| serves to longitudinallyshift said shaft within the sleeve 23 in a disengaging or releasingdirection by virtue of the abutment of the disk 29 with the housing ofthe motor.

While the preferred embodiment of the invention has been illustrated anddescribed herein, it will be understood that changes may be made in theconstruction within the scope of the appended claims without departingfrom the spirit of the invention.

I claim:

1. In a windshield wiper motor, a housing comprising a pair of similarcup-shaped parts, each having a cylindrical bore in its inner portionand an enlarged interior dimension adjacent its mouth, said cylindricalbore bein interrupted by a longitudinal groove extending from its innerend to a point spaced from said enlarged portion and communicating witha lateral aperture, a preformed sleev fitting snugly in each part withits inner end terminating outwardly of the inner end of said groove,said sleeve and groove cooperating to define a passage open at saidaperture and at the inner end of said bore, and means for securing saidparts together at their open ends and in axial alignment.

2. The construction defined in claim 1, wherein said housing partsconstitute metal castings and said sleeves are preformed and have apress fit in said housing parts.

3. The construction defined in claim 1, wherein said housing parts eachhas a circumferential interior Shoulder between said cylindri al andenlarged bore portions and said sleeves each terminate in a fiared endportion bearing against said shoulder.

4. In a windshield wiper motor, a pair of cupshaped parts each having aninlet aperture and a longitudinal passage communicating with saidaperture and open at the inner end of said part,

each part having a longitudinal insert in its exterior surface, saidapertures opening at said inset surface, means for securing the open endportions of said parts together in register, and a preformed valve unithaving a pair of longitudinally spaced outlet ports and of a shape tofit in said insets in face engagement with said parts, and meanssecuring said valve unit to said parts, said valve outlet portsregistering with said apertures.

5. In a fiuid-pressure-actuated windshield wiper motor, a housing havingan elongated bore, a piston unit reciprocable in said bore, said housinghaving a pair of passages each communicating with said bore at one endthereof and a pair of longitudinally spaced apertures each communicatingwith a bore; a preformed valve unit secured to said housing, said valveunit comprising a housing having an elongated bore open at one end, anintake port, a longitudinal passage communicating with said intake portand communicating with said bore at its ends, a second longi tudinalpassage communicating with said bore at its opposite ends, and a pair oflongitudinally spaced delivery ports communicating with said bore andregistering with said apertures; a valve unit shiftable in said bore andcomprising an elongated rigid member mounting two spaced sets of spacedseals, said valve unit having two operative positions, one set of sealsestablishing communication between an end of said first longitudinalpassage and a delivery port, and the other set of seals confining insaid bore and therebetween fluid from the other delivery port in eachposition of said valve unit; and means actuated by said piston unit forshifting said valve unit from one operative position to the other.

6. The construction defined in claim 5, wherein said last named meansincludes a lost motion member and a spring pressed quick-throw memher.

'7. The construction defined in claim 5, wherein the portions of saidrigid member between said sets of seals are of smaller cross-sectionalsize than said bore and the portions of said member which mount saidseals are of larger cross-sectional size.

8. A valve adapted for use in a fluid pressure actuated windshieldwiper, comprising an elongated body having a longitudinal bore open atone end, an intake passage having a pair of outlets communicating withsaid bore at longitudinally spaced points, a pair of delivery portsspaced 1ongitudinally from each other and from the outlets of saidintake passage, and a by-pass communicating with opposite ends of saidbore, a valve element, and means for shifting said valve element betweentwo spaced operative positions, said Va1Ve element including fourlongitudinally spaced sealing elements and having portions between theoutermost seals and the seals adjacent thereto of smallercross-sectional size than the cross-sectional size of said bore, one ofsaid outermost seals being positioned between a delivery port and theadjacent outlet of said intake passage and the other outermost sealbeing positioned clear of the other delivery port and the adjacentoutlet of said intake passage in each operative position of said valveelement.

9. The construction defined in claim 8, wherein said body has anelongated slot communicating with and extending radially from thecentral portion of said bore, and an arm carried by said 9 valve elementbetween the inner seals and projecting freely through said slot.

10. a windshield Wiper motor, a housing having an elongated cylindricalbore, a pair of ens reciprocable in said bore, a rigid member connectingsaid pistons, a sleeve journaled in said housing and adapted to berocked by movement of said pistons, said sleeve being open at itsopposite ends and at opposite sides of said housing, a shaft detaehablymounted in and slidable endwise from said sleeve, means accessibleexteriorly of said housing for looking said shaft for conjoint rotationwith said sleeve, a quick-throw valve actuator journaled on said sleeveadjacent to said rigid member, and a pair of spaced stops adjusti0 ablymounted on said rigid member on opposite sides of and engageable withsaid actuator to trip the actuator.

References Sited in the file of this patent UNITED STATES PATENTS NumberName Date 899,999 Osmer Sept. 29, 1908 1,834,607 Dove Dec. 1, 19312,224,708 Van Sittert Dec. 10, 1940 2,246,535 Playfair June 24, 19412,264,658 Campbell Dec. 2, 1941 2,385,084 Koppelman Sept. 18, 19452,415,607 Sacehini Feb. 11, 1947 2,594,856 Bluhm Apr. 29, 1952

